Assuming an ebullioscopic constant of 0.512 °C/m for the water, If you add 30.0g of salt to 3.75kg of water, the boiling-point elevation will be 0.140 °C and the boiling-point of the solution will be 100.14 °C.
<h3>What is the boiling-point elevation?</h3>
Boiling-point elevation describes the phenomenon that the boiling point of a liquid will be higher when another compound is added, meaning that a solution has a higher boiling point than a pure solvent.
- Step 1: Calculate the molality of the solution.
We will use the definition of molality.
b = mass solute / molar mass solute × kg solvent
b = 30.0 g / (58.44 g/mol) × 3.75 kg = 0.137 m
- Step 2: Calculate the boiling-point elevation.
We will use the following expression.
ΔT = Kb × m × i
ΔT = 0.512 °C/m × 0.137 m × 2 = 0.140 °C
where
- ΔT is the boiling-point elevation
- Kb is the ebullioscopic constant.
- b is the molality.
- i is the Van't Hoff factor (i = 2 for NaCl).
The normal boiling-point for water is 100 °C. The boiling-point of the solution will be:
100 °C + 0.140 °C = 100.14 °C
Assuming an ebullioscopic constant of 0.512 °C/m for the water, If you add 30.0g of salt to 3.75kg of water, the boiling-point elevation will be 0.140 °C and the boiling-point of the solution will be 100.14 °C.
Learn more about boiling-point elevation here: brainly.com/question/4206205
The volume of H₂ evolved at NTP=0.336 L
<h3>Further explanation</h3>
Reaction
Decomposition of NH₃
2NH₃ ⇒ N₂ + 3H₂
conservation mass : mass reactants=mass product
0.28 NH₃= 0.25 N₂ + 0.03 H₂
2 g H₂ = 22.4 L
so for 0.03 g :
Answer:
B: All of the choices!
Explanation:
Choice 1: Simply, there is no current without voltage, so it DOES cause current.
Choice 3: Voltage DOES push free electrons around a circuit. Without it, free electrons will move around between atoms, but randomly, so they wouldn't be much use.
Choice 4: Voltage IS measured in volts, so this option is true as well.
Choice 2: Voltage is all of those answers, so it is true! :D
Hope i helped! :]
Hey there!
The pH of a weak base (in this case, pyridine is a weak base) is calculated by using the weak base equation, and then solving it.
C5H5N; Kb= 1.7 x 10⁻⁹
pH = -log [H⁺]
we can also say that pH = 14 + log [OH⁻]
Plugging into the weak base equation, we know that Kb = [OH⁻][BH⁺] / [B]
This can be solved using an ice chart, which will then simplify to :
Kb = [x][x] / [0.50-x]
We can assume that x is very small in comparison to the 0.5 , so we consider it zero.
Then plug in and solve for x. 1.79 *10-9 = x² / 0.5
x = 2.992 * 10⁻⁵
ince X is equal to the [OH⁻] concentration, we can plug it into the second pH equation, and get the pH!
pH = 14+ log 2.99 * 10⁻⁵
pH = 9.48
Hope that helps!
